1. Field of the Invention
The present invention relates to a job processing method for a printing system capable of accepting a plurality of jobs, and a printing system.
2. Description of the Related Art
In a conventional printing industry, a publication is issued through work steps such as entry of a document, designing of the document, layout editing, comprehensive layout (presentation by printing), proofreading (layout correction and color correction), proof (proof print), block copy preparation, printing, post-processing, and shipping.
In the conventional printing industry, an offset reproduction printing press is often used in the printing step, and the block copy preparation step is inevitable. However, once the block copy is prepared, it is difficult and disadvantageous in cost to correct the block copy. In block copy preparation, therefore, careful proofreading (i.e., careful layout check and color confirmation) is indispensable. Some period of time is generally taken until a publication is issued.
Most apparatuses used in respective work steps are bulky and expensive. A considerable expert knowledge is necessary, and know-how of experts is indispensable.
In this situation, so-called POD (Print On Demand) printing systems using electrophotographic and inkjet printing apparatuses are proposed recently.
(See Japanese Patent Laid-Open Nos. 2004-310746 and 2004-310747).
However, there is room for further study in commercializing a printing system suited even to the POD environment. For example, various types of sheets (e.g., print media to be printed by a printing apparatus) are available on the POD market. “Multi-feed (double feed)” sometimes occurs to simultaneously feed two sheets from a sheet feeder. The multi-feed stops the printing operation of the printing system, decreasing the throughput.